CNS nutrition - Parks Flashcards
Diet may have a positive effect on what disease?
Alzheimer’s. Studies have shown that B vitamin treatment slowed shrinkage of the brain.
Vitamin B1 is called what?
Thiamine
What is a disease of thiamine deficiency?
Beri Beri
What diseases is associated with Thiamine deficiency and CNS effects?
Wernickes’s and Wernicke-Korsakoff syndrome.
What does Wernicke’s encephalopathy cause?
- ophthalmoplegia - affects eye muscles
- cerebellar ataxia
- mental impairment - confused, disoriented, indifferent
What is the pathology of Wernicke’s encephalopathy?
Foci of hemorrhage and necrosis in the maxillary bodies (also increased vascularity and edema) and walls of the 3rd and 4th ventricles and the thalamic nuclei.
Wernicke’s Korsakoff causes what?
Memory of new events is seriously impaired so these patients may confabulate.
Does Wernicke’s Korsakoff affect older memories?
No.
What is the pathology of Wernicke’s Korsakoff syndrome?
Similar to Wernicke’s encephalopathy but there may be prominent degeneration of the neurons the walls of the 4th ventricle and medial thalamic nuclei.
Thiamine deficiency produces what?
A diffuse decrease in cerebral glucose utilization that results in mitochondrial damage.
What is the difference between Wernicke’s encephalopathy and Wernicke’s Korsakoff syndrome?
Wernicke’s Korsakoff syndrome is chronic Thiamine deficiency (clinical term because it requires the confabulation and memory problems) and Wernicke’s encephalopathy is acute.
What is one function of the maxillary bodies?
Memory.
What patient’s are at risk for Wernicke’s encephalopathy?
- Chronic alcoholics- poor diet
- chronic gastritis
- gastric carcinoma
- persistent emesis
- gastric bypass
- prisoner’s who are fed a poor diet
How does alcohol affect Thiamine?
It directly impairs the absorption of thiamine.
What is the treatment for Wernicke’s?
Parenteral Thiamine - IM or IV.
How is Wernicke’s diagnosed?
Clinical picture plus X-ray with contrast to look at maxillary bodies.
What is parasthesia?
Painful, tingles and numbness type feeling.
What is the normal value for serum methylmalonic acid?
Less than 400 nmol/Liter.
If a patient has impaired positional and vibrational sense?
The posterior columns of the spinal column.
What is the normal value for serum homocysteine?
Less than 14 umol/L.
What does B12 deficiency cause?
Reversible (if treated early) bone marrow failure and demyelination of the CNS neurons.
B12 deficiency can cause what?
Combined demyelination and degeneration of neurons in the dorsal and lateral columns of the spinal cord.
WHat is necessary for B12 absorption?
Intrinsic factor.
What can Crohn’s disease cause?
Lack of absorption of B12 and intrinsic factor.
What conditions can cause B12 deficiency?
- pernicious anemia - ie. atrophic gastritis
- gastrectomy - possibly due to cancer of stomach, ulcers etc.
- impaired malabsorption from intestines
- bariatric surgery - ie. laparoscopic sleeve gastrectomy
- inadequate diet or vegetarianism
Where is intrinsic factor secreted?
Parietal cells in the funds of the stomach.
What symptoms can vitamin B12 deficiency cause?
Myelopathy, neuropathy, dementia and depression.
